THE LUNGS. IO9 



mouth's course of the remedy before making such an effort; the 

 beauty of Arsenicum is that it not only does not interfere with the 

 training operations but in reahty acts as a tonic and the horse 

 trains on better while taking it; the same remarks of course apply 

 with equal force to hunters or any other class of horse. 



THE IvUNGS. 



The consideration of the various forms of disease which affect 

 the lungs, must for the sake of distinction be divided into three 

 classes, but before defining them it is desirable, if not necessary, 

 for a proper appreciation of the subject, to explain as simply as 

 possible the construction of these vitally important organs. Com- 

 plex as the whole organism is, and necessary for the maintenance 

 of health}' life as each individual set of organs may be, probably 

 the lungs hold the post of honor in relative importance when the 

 all important topic of how life in its pristine vigor is to be main- 

 tained comes under consideration. In the first place let us inquire 

 of what do lungs consist; taken into the hands and examined 

 under pressure they feel not unlike a piece of sponge; there is a 

 certain amou'it of elasticity about them which under pressure 

 effects a sort of rebound, after being compressed into a small 

 compass expansion takes place naturally and they assume their 

 original shape; this physical fact is accounted for by their con- 

 struction; the lungs, speaking roughly, consist of a net-work of 

 hollow tubes (called bronchial tubes) of var3-ing sizes supported 

 by connective tissue, called the parenchyma or true lung sub- 

 stance, while in company with the bronchial tubes blood vessels 

 (both arteries and veins) follow much the same course among the 

 connective tissue or lung substance; the w^hole mass is' then 

 encased in a fine mesh-like membrane which has a glazed external 

 surface called the pleura, which helps in some measure to keep 

 the lungs in the form and shape they naturally assume; it must 

 be understood that the bronchial tubes described as one of the 

 principal divisions of the lungs, are in realit}^ continuations of the 

 trachea or windpipe, which in the first place divides into two 

 branches, one for each lung; these main branches then enter the 

 lung and thereafter divide and subdivide into smaller and still 

 smaller branches until they are so fine that it needs powerful 

 magnifying aid to discern their shape and course, ultimately 



